Hydroquinone diacetamide azo compounds



United States Patent 3,201,384 DROQUWONE DHACETAMTDE AZO CUMPUUNDS Milton Green, Newton Center, Mass, assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Filed (let. 23, 1962, 'Ser. No. 232,578 2 Claims. (Cl. 260-160) This application is in part a continuation of application Serial No. 711,811, filed January 29, 1958, now abandoned.

This invention relates to photography and more particularly to products, compositions and processes for the development of photosensitive silver halide elements.

It is one object of the present invention to provide novel processes and compositions for the development of silver halide emulsions, in which novel colored developing agents are used.

Another object is to provide novel processes and compositions for the development of silver halide emulsions, in which the novel developing agent is capable of developing an exposed silver halide emulsion and imparting a reversed or positive colored image of the developed image to a superposed image-receiving material.

A further object is to provide novel silver halide developing agents and novel products, processes and compositions suitable for use in preparing monochromatic and multichromatic photographic images.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the processes involving the several steps and the relation and order of one or more of such steps with respect to each of the others, and the products and compositions possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

The objects of this invention may be accomplished by the use of certain novel dyes which have the ability to develop images present in an exposed silver halide emulsion; thus they may be referred to as dye developers. These novel dyes or dye developers will be further described hereinafter.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description.

The photographic processes and compositions disclosed herein are particularly useful in the treatment of an exposed silver halide emulsion, whereby a positive dye image may be imparted to another element, herein referred to as an image-carrying or image-receiving element.

US. Patent No. 2,983,606, issued May 9, 1961, to Howard G. Rogers, discloses diffusion transfer processes wherein a photographic negative material, such as a photographic element comprising an exposed silver halide emulsion, is developed in the presence of a dye developer to impart to an image-receiving layer a reversed or positive dye image of the developed image by permeating into said emulsion a suitable liquid processing composition and bringing said emulsion into superposed relationship with an appropriate image-receiving layer. The inventive concepts herein set forth provide novel dye developers for use in such processes.

In carrying out the process of this invention, a photosensitive element containing a silver halide emulsion is exposed and wetted with a liquid processing composition, for example by immersing, coating, spraying, flowing, etc., in the dark, and the photosensitive element superposed prior to, during or after wetting, on an image-receiving element. In a preferred embodiment, the photosensitive element contains a layer of dye developer, and the liquid processing composition is applied to the photosensitive element in a uniform layer as the photosensitive element is brought into superposed position with an image-receiving element. The liquid processing composition permeates the emulsion to provide a solution of dye developer substantially uniformly distributed therein. As the exposed silver halide emulsion is developed, the oxidation product of the dye developer is immobilized or precipitated in situ with the developed silver, thereby providing an imagewise distribution of unoxidized dye developer dissolved in the liquid processing composition. This immobilization is apparently due, at least in part, to a change in the solubility characteristics of the dye developer upon oxidation, and especially as regards its solubility in alkaline solutions. it may also be due, in part, to a tanning effect on the emulsion by the oxidized developing agent. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving layer. The image-receiving layer receives a depthwise diffusion, from the emulsion, of unoxidized dye developer, without appreciably disturbing the imagewise distribution thereof, to provide a reversed or positive, colored image of the developed or negative image. The imagereceiving element may contain agents adapted to mordant or otherwise fix the diffused, unoxidized dye developer. lmbibition periods of approximately one minute have been found to give good results, but this contact period may be adjusted where necessary to compensate for variations in temperature or other conditions. The desired positive-image is revealed by stripping the image-receiving layer from the silver halide emulsion at the end of the imbibition period.

The dye developers of this invention may be utilized in the photosensitive element, for example in, on or behind the silver halide emulsion, or they maybe utilized in the image-receiving element or in the liquid processing composition. ln a preferred embodiment, a coating or layer of the dye developer is placed behind the silver halide emulsion, i.e., on the side of the emulsion adapted to be located most distant from the photographed subject when the emulsion is exposed and preferably also adapted to be most distant from the image-receiving layer when in superposed relationship therewith. Placing the dye developer behind the emulsion layer, as in the preferred embodiment, has the advantage of providing increased contrast in the positive image, and also minimizes any lightltering action by the colored dye developer. In this preferred embodiment, the layer of dye developer I may be applied by using a coating solution containing about 0.5 to 8%, by weight, of the dye developer. Similar concentrations may be'used if the dye developer is utilized as a component of the liquid processing composition. In an especially useful mode of disposing the dye developers in the photosensitive elements, the dye developer is dissolved in a water-immiscible solvent and then dispersed in a gelatin coating solution.

The liquid processing composition which is used in the processes herein disclosed comprises at least an aqueous solution of an alkaline compound, for example, diethylamine, sodium hydroxide or sodium carbonate, and may contain the dye developer. In some instances, it may contain an additional silver halide developing agent. If the liquid processing composition is to be applied to the emulsion by being spread thereon, preferably in a relatively thin, uniform layer, it may also include a viscosityincreasing compound constituting film-forming material of the type which, when spread over a water-absorbent A preferred film-forming material is a high molecular weight polymer such as a polymeric, water-soluble ether inert to an alkali solution, as, for example, a hydroxyethyl cellulose or sodium carboxymethyl cellulose. Other film-forming materials or thickening agents whose ability to increase viscosity is substantially unaffected when left in solution for a long period of time may also be used.

The novel dye developers of this invention may be represented by the formula:

C11 -(['|J1TIX R XITI-$|J-GH wherein each R is hydrogen, or a lower alkyl group, e.g., methyl, ethyl, propyl, etc.; the

radical is the residue of a dye molecule having at least one reactive primary or secondary amino group therein and X being the dye molecule exclusive of said amino group. The grouping contains the chromophoric system of the dye from which it is derived. In the preferred embodiment,

is the radical of an azo or anthraquinone dye,

HNX 1'1 and the amino substituent is bonded to a carbon atom of the X moiety of the dye molecule. In the case of anthraquinone dyes, the amino substituent may be directly substituted on the anthraquinone nucleus or bonded to a carbon atom of an alkylamino substituent which in turn is bonded directly to the anthraquinone nucelus. In the case of azo dyes, the amino substituent may be directly substituted on a nuclear carbon atom of an aromatic or heterocyclic nucleus, e.g., to an azo coupler radical such as naphthol, pyrazolone couplers, etc.

The above compounds may be prepared by reacting two moles of an amino-substituted dye, or of an amino compound which may be further reacted to form a dye, with one mol of a compound of the structure:

followed by hydrolysis of the acyl groups.

Another method of preparing the novel compounds used in the processes of this invention is by reacting an amino-substituted dye, or an amino compound which is capable of being further reacted to form a dye, with a diester of 2,5-hydroquinonediacetic acid of the structure:

CHg-fi-O-R o R-O-(flJ-CH It should be noted that it is within the scope of this invention to use mixtures of the novel compounds in the processes herein disclosed. Thus, in certain instances when a mixture of the monoamide and diamide are produced in the synthesis, separation is unnecessary.

The reactive primary or secondary amino-substituted dyes, from which the 2-phenylazo-4-amin0-1-naphtho1 l NII, 1-p-amin0pl1enyl-'3-methyl-4-p-tolylazo-S-pyruzolone 2- [4'-phenylazo-1'naphthylazo] -4-amino-1-naphth 01 (I) lTIH-CH2CHPNH2 O NH-CHzCHr-OH '1- (fl-aminoethylamino)-4- (B-hydroxyethylamlno)- anthraquinone As an example of an amino compound which may be reacted with hydroquinone diacetyl chloride and which is further capable of being reacted to form a dye, e.g., by azo coupling, mention may be made of 1-phenyl-3-amino- S-pyrazolone.

The preferred compound for carrying out the processes of this invention is: 7

N,N'-biS-[3'-J( f'phenyl-d'-p-chlorophenylaz0-5'-pyrazolony1) -2;5-hydroquinone-diacetamide The following nonlimiting example illustrates the preparation of a novel dye developer within the scope of this invention.

Example 1 2,5 bis-carbethoxybenzene-p-diacetic acid was prepared by dissolving 0.08 mol of sodium hydroxide in '50 cc. of water, deoxygenated with nitrogen, and then adding 002 mol of 2,5dihydroxybenzene diacetic acid. The solution was cooled in an ice bath and 0.08 mol of ethyl chloroformate was gradually added to the solution with constant stirring. A pellet of sodium hydroxide and a small amount of ethylchloroforrnate were added to the solution to insure completeness of reaction. 10% hydrochloric acid was added to the solution until precipitation was completed. The product was extracted with ethyl ether and the ether extract in turn was extracted with a 10% sodium bicarbonate solution. The product was precipitated from the sodium bicarbonate solution by the addition of 10% hydrochloric acid and extracted with ether. The ether extract was washed with water, dried over anhydrous magnesium sulfate and evaporated to produce 2,S-bis-carbethoxybenZene-p-diacetic acid, melting at 218 to 220 C. A mixture of 7.4 gm. (0.02 mol) of 2,5-bis-carbethoxy benzene-p-diacetic acid (prepared as above) and 55 ml. (0.77 mol) of thionyl chloride was refluxed for two hours. Excess thionyl chloride was removed under vacuum and the residue was taken up in 50 ml. of hot benzene. Upon cooling, 6.5 gm. of 2,5-biscarbethoxybenzene-p-diacetyl chloride as White needles,

, melting at 1 61 to 162 C., was obtained. A carbon,

hydrogen and chlorine analysis of the product shows the following:

Calculated 47. 3 4. 0 17. 4 Found 47. 2 4. 0 17. 3

A mixture of 2 gm. of 1-phenyl-3-amiuo 5-pyrazolone, 2 gm, of the acid chloride (prepared as above) and 20 cc. of o-dichlorobenzene was refluxed for one hour (hydrogen chloride being involved). After slight cooling, the

product was separated by pouring the reaction mixture Percent Calculated 12.3 Found 12.3

1.9 gm. (0.015 mol) of p-chloroaniline were dissolved in 4 ml. of concentrated acid and 20 ml, of water. The solution was cooled to C. by adding ice, and diazotization was carried out by adding 1.0 gm. (0.015 mol) of sodium nitrate. A final liquid volume of 54 ml. was

obtained. 38 ml. (0.011 mol) of this solution was added to 3.4 gm. (0.005 mol) of N,N'-'bis-[3-(1'-phenyl-5- pyrazolonyl) ]-2, 5-dicarbethoxybenzene-p-diametamide in 40 ml. of pyridine, 60 ml. of acetone, 20 ml. of saturated bicarbonate and 40 ml. of water. The resulting slurry was stirred for several hours at which time a test for excess coupler was negative, indicating substantially complete bis-dye formation. The slurry was filtered and washed with water. The filter cake from the above was added under nitrogen to a solution of 5 gm. of potassium hydroxide in 70 ml. of ethanol and 10 ml. of Water. The flask was evacuated and the solution was warmed for a few minutes. Upon precipitating with hydrochloric acid and crystallizing from ethanol, N,N'-bis-[3-(1-phenyl- 4' -'p chlorophenylazo 5' pyrazolonyl)] 2,5 hydroquinone-diacetamid-ehydrochlo-ride was obtained as a tan solid, melting at 198 to 200 C. The spectral absorption curve of the product in ethanol exhibits a A at 396 mp. of e=34,500

As noted above, the novel dye developers of this invention may also be prepared by reacting a 2,5-bise acyloxy'oenzene-p-diacetyl-chloride compound with an amino-substituted dye and hydrolyzing off the acyl' radicals. Thus, for example, N,N'-bis-[4-(1'-hydroxy-2'- phenylazonaphthyl) ]-2,5-l1ydroquinone-cliacetamide may be prepared by reacting 2,5-bis-carbethoxybenzene-p-diacetyl chloride with 2-phenylazo-4-amino-1-naphthol, and hydrolyzing oil the carbethoxy radicals of the resulting amido compound.

The following example shows by way of illustration and not by way of limitation the photographic usage of the novel dye developers of this invention.

Example 2 A photosensitive element was prepared by coating a gelatin-coated film base with an acetone-methanol solution (4 to 1 by volume) containing 3% of N,N'-bis-[3'- (1 phenyl 4'-p-chlorophenylazo-S'pyrazolonyl)]-2,5- hydroquinone-diacetamide-hydrochloride and 4% of cellulose acetate hydrogen phthalate and, upon drying, coating this film with a silver iodobromide emulsion. After exposure, the photosensitive element was developed by spreading between the photosensitiveelement and a superposed image-receiving element an aqueous processing composition containing:

Percent Sodium. carboxyrnethyl cellulose 4.5 1-phenyl-3-pyrazo1id0ne 0.2 Sodium hydroxide 2.0 Potassium bromide 0.2

The image-receiving element comprised a cellulose acetate-coated baryta paper which in turn has been coated with a solution comprising 4% Nylon Type P8 (trade name for N-methoxymethyl polyhexamethylene adipamide) in aqueous isopropanol. After development, the image-receiving element was separated to reveal a yellow positive dye image.

In the present process and in dye developer processes, in general, the dye developer is preferably employed in a concentration such that it will be fully reacted in completely exposed areas.

Through the use of suitable oxidizing agents, such as mercuric acetate, benzoquinone, etc., the novel dye developers used in the processes of this invention may be converted to the equally novel dioxophenyl derivatives which may be represented by the formula:

wherein X and R have the same meaning as above. Such quinones are useful as dyes and as pigments.

It should be noted that certain dye developers are sensitive to pH change. Since the dye developer is rendered efiective by solution in an aqueous alkaline liquid processing composition, it accordingly is necessary to assure that the environment in which the transferred and unreacted dye developer is deposited has or is capable of attaining the requisite pH value afiording the desired color to the diffused dye developer. This may be accomplished by use of a volatile basic compound such as diethylamine in the liquid processing composition. It sodium hydroxide is utilized in the processing liquid, it becomes carbonated after processing and by contact with the air and this is effective to provide the desired pH change. Further control of the pH of the transferred and unreacted dye developer may be had by utilizing an image-receiving element which is difiiculty penetrable by alkali, for example an appropriate nylon such as N-methoxymethyl polyhexamethylene adipamide, or by the use of a receiving element in which an acid or an acide-forming compound, e.g., oleic acid, has been incorporated.

It will be noted that the novel dye developers of this invention contain two dye moieties bonded to a single developing substituent. These dye developers have a particular advantage over dye developers containing a single chromophoric unit, in that the dye developers of this invention provide twice as many chromophoric units per unit of dye developer transfer-red and thus provide a method for intensifying the density of the transfer image. Prior to the present invention, it was not believed that such compounds were useful since it was not heretofore believed by those skilled in the art that the dye developers of the present invention could in fact be used in photographic systems such as described herein. Previously, it was believed by those skilled in the art that the compounds of the present invention would be incapable of developing an exposed silver halide invention, because of steric hindrance and/or the molecular structure wherein the developing function is positioned in the center of a relatively large molecule. Thus, as far as is known, it was never obvious to those skilled in the art, prior to the present invention, to employ such dye developers in photographic processes, products and compositions such as described and claimed in the aforementioned U.S. Patent No. 2,983,606.

The dye developers of this invention are also useful in integral multilayer photosensitive elements for use in multicolor diffusion transfer processes. As an example of such photosensitive elements, mention may be made of the photosensitive elements disclosed and claimed in the copending US. application of Edwin H. Land and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956, wherein at least two selectively sensitized photosensitive strata tare superposed on a single support and are processed, simultaneously and without separation, with a single common image-receiving element. A suitable arrangement of this type comprises a support carrying a red-sensitive silver halide emulsion stratum, a green sensitive silver halid emulsion stratum and a blue-sensitive silver halide emulsion stratum, said emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer and a yellow dye developer. In one of the preferred embodiments of photosensitive elements of this type, the dye developers are disposed in separate alkali-permeable layers behind the photosensitive silver halide emulsion stratum with which they are associated.

The photosensitive elements within the scope of this invention may be used in roll film units which contain a plurality of photosensitive frames. The photosensitive elements of this invention are especially useful in composite roll film intended for use in a Polaroid Land Camera or a similar camera structure such, for example, as the camera forming the subject matter of U8. Patent No. 2,435,717, issued to Edwin H. Land on February 10, 1948. In general, such composite roll films comprise a photosensitive roll, a roll of image-receiving material and a plurality of pods containing an aqueous alkaline processing solution. The rolls and pods are so associated with each other that, upon processing, the photosensitive element may be superposed on the image-receiving element and the pods may be ruptured to spread the aqueous alkaline processing solution between the superposed elements. The nature and construction of the pods used in such units are well known to the art. See, for example, US. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

It will be noted that the liquid processing composition may contain one or more auxiliary or accelerating silver halide developing agents, such as p-methylaminophenol (Metol); 2,4-diaminophenol (Amidol); benzylaminophenol; hydroquinone; a substituted hydroquinone such as toluhydroquinone, phenylhydroquinone, or 4-methylphenylhydroquinone; or a 3-pyrazolidone such as 1- phenyl-3-pyrazolidone. These silver halide developing agents are substantially colorless, at least in their unoxidized form. It is possible that some of the dye developer oxidized in exposed areas may be oxidized by an energy transfer reaction with oxidized auxiliary developing agent.

In addition, development may be effected in the presence of an onium compound, particularly a quaternary ammonium compound, in accordance with the processes disclosed and claimed in the copending application of Milton Green and Howard G. Rogers, Serial No. 50,851, filed August 22, 1960.

The dye developers of this invention may be used also in conventional photographic processes, such as tray or tank development of conventional photosensitive films, plates or papers to obtain black-and-white, monochromatic or toned prints or negatives. By way of example, a developer composition suitable for such use may comprise an aqueous solution of approximately 12% of the dye developer, 1% sodium hydroxide, 2% sodium sulfite and 0.05% potassium bromide. After development is completed, any unreacted dye developer is washed out of the photosensitive element, preferably with an alkaline washing medium or other medium in which the unreacted dye developer is soluble. The expression toned is used to designate photographic images wherein the silver is retained with the precipitated dye, whereas monochromatic is intended to designate dye images free of silver.

It should be noted that the dye developers of this medium are self-suflicient to provide the desired color image and do not depend upon coupling reactions to produce the desired color. They thus provide a complete departure from conventional photographic color processes in which the color is produced by a coupling reaction between a color former or coupler and the oxidized developing agent, as well as so-called auto-coupling processes in which color is obtained by a reaction of the oxidized developing agent with unoxidized developing agent.

It will be apparent that, by appropriate selection of the image-receiving element from among suitable known opaque and transparent materials, it is possible to obtain either :a colored positive reflection print or a colored positive transparency. Likewise, the inventive concepts herein set forth are adaptable for multicolor work by the use of special photographic materials, for example, film materials of the type containing two or more photosensitized elements associated with an appropriate number of image-receiving elements and adapted to be treated with one or more liquid processing compositions, appropriate dye developers suitable to impart the desired subtractive colors being incorporated in the photosensitized elements or in the liquid processing compositions. Example of such photographic materials are disclosed in US Patent 2,647,049 to Edwin H. Land.

As examples of using image-receiving materials, mention may be made of nylon, e.g., N-methoxymethyl-polyhexamethylene adipamide, polyvinyl alcohol, and gelatin, particularly polyvinyl alcohol or gelatin containing a dye mordant such as poly-4-vinylpyridine. The image-receiving element also may contain a development restrainer, e.g., 1-phenyl-S-mercaptotetrazole, as disclosed in the copending application of Howard G. Rogers and Harriet W. Lutes, Serial No. 50,849, filed August 22, 1960.

The dye developers herein set forth are also useful in the formation of colored images in accordance with the photographic products and processes described and claimed in US. Patent No. 2,968,554,issued to Edwin H. Land on January 17,1961.

The novel compounds herein disclosed are also suitable for use as dyes for textile fibres, such as nylon.

In the preceding portions of the specification, the expression color has been frequently used. This expression is intended to include the use of a plurality of colors to obtain black.

Copending US. application, Serial No. 232,613, filed concurrently herewith, claims the photographic utilization of the novel compounds of the present invention.

10 Since certain changes may be made in the above products without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

wherein each R is selected from the group consisting of hydrogen and lower alkyl radicals; and

is the radical of a member of the group consisting of phenylazo-naphthol, phenylazo-pyrazolone and phenylazo-naphthylaZo-naphthol dyes of the formula wherein X is the dye molecule exclusive of said substituent and said nitrogen atom is bonded directly to a nuclear carbon atom of said dye molecule.

2. N,N bis [3 (1'-phenyl-4-p-chlorophenylazo-5'- pyrazolonyl) ]-2,5-hydroquinone-diacetamide.

No references cited.

CHARLES B. PARKER, Primary Examiner. 

1. A COMPOUND OF THE FORMULA: 